The aim is to put 8 coloured dots on the 8×8 board so that
no two dots are in the same row, column, or diagonal. This is often called
the 8 Queens Problem, as it is equivalent to placing 8 queens on a chessboard
so that no two pieces attack each other.
Two or three red dots are given, and you have to supplement
them with green dots to make an 8 queens pattern.

In the Blockade levels (indicated by red numbers) the red dots do
not take part in the pattern but merely restrict the movement of the green dots.
You have to place a green dot in every column to make an 8 queens pattern, but
cannot move a green dot down past a red dot.

Simply click on the spots on the board where you want a green dot to be, or
on the top edge of the puzzle to remove a dot from a column of the board.

Normal levels are shown with a green or yellow level number, and blockade levels with
a red number. Most levels have a unique solution. In some levels there are two solutions,
and this is indicated by a dot after the level number.

The 'Check' button will show any mistakes you have made in the 8 queens
pattern by lighting up two dots that are in the same row, column or diagonal,
or by lighting up a column that is still missing a dot. If there is more than
one mistake you can click the button several times to see each one in turn.
The 'Solution' button will give you a link to a site where you can find
the solution to the current level.The 'Solution' button will give you a solution to the current level. If
you click it again it will show another solution if it exists.

This game is almost the same as a real Frustr8tor, but there are some things
to be aware of when you play with the real thing, in particular how to use the back
side of the puzzle.

The numbers on the back of the puzzle allow you to set a level. Choose any of
the numbers, and bring up the red slider from the bottom until it is next to the
number. The little arrow near the number should be pointing in the direction of
the red slider.

You have to place a red slider next to each occurrence of your chosen level number.
To make this easier, the letter next to the number tells you which column you
should set next. In the example shown here, for level 20 the next column to set is F.

The letter labels are at the bottom of the columns. Check the arrows to ensure you
use the slider belonging to the column. In the example picture the F slider is moved up
next to our chosen level number, 20. The letter C indicates the next column to set, but
column C is already set so we are finished.

Once you have set the red sliders for a level, turn it over and play. Be careful not to
move the red dots, and only move the green ones. In normal play you don't need to put a
green dot in a column that already contains a red one.

The back of the original version of the puzzle looked slightly different.

Original

It did not have those helpful letters, but instead showed two or three dots
on the arrow to indicate how many red sliders you needed to set.